Field
The present invention relates to a cartridge that is mounted to a liquid ejection apparatus such as a printer and is configured to supply a liquid such as pigment ink.
Related Art
Pigment ink includes particles of pigment dispersed in a solvent. The pigment ink contained in an ink pack (liquid container assembly) is thus likely to cause concentration unevenness that the concentration of the pigment is lower on an upper side and higher on a lower side, due to sedimentation of the pigment. Using the pigment ink of such concentration unevenness supplied to an inkjet printer for printing is likely to cause the density unevenness in printing and deteriorate the printing quality.
A cartridge equipped with a mechanism for stirring the pigment ink contained in an ink pack has been proposed, in order to avoid such deterioration of the printing quality. A cartridge disclosed in JP 2005-35025A has an ink pack including a flexible liquid container configured to contain ink therein, a flexible air bag having the shape restorability, and a casing configured to place the ink pack and the air bag therein. The casing is in a flat rectangular parallelepiped shape having a longer dimension in a mounting direction and a shorter dimension in a width direction perpendicular to the mounting direction. The air bag is placed in a location adjacent to the ink pack in the width direction. An ink supply port is provided in a front face of the casing in the mounting direction to supply the pigment ink from the ink pack to outside. An air flow port is also provided in the front face of the casing to introduce the air into the casing and communicate the casing with the atmosphere. An air communicating port is provided in a side face of the casing to communicate the air bag with the atmosphere.
In the process of supplying the pigment ink to a printer, for example, during a printing operation, the pressurized air is introduced through the air flow port into the casing. This causes the ink pack to be pressurized from outside and thereby causes the pigment ink contained in the ink pack to be supplied through the ink supply port toward the printer. When the pressurized air is introduced into the casing, the air bag is compressed by the pressure of the pressurized air. On completion of the supply of the pigment ink to the printer, inside of the casing is open to the atmosphere via the air flow port. When the casing is open to the atmosphere, the internal pressure of the casing is decreased. The air bag is accordingly expanded to the original shape by the shape restorability. In the course of restoring the air bag to the original shape, the air bag presses the ink pack to deform the ink pack. This stirs the pigment ink contained in the ink pack and reduces the concentration unevenness of the pigment ink in the ink pack.
Introducing the pressurized air into the air bag described in JP 2005-35025A enables the air bag to be actively expanded by the pressurized air. This configuration causes the ink pack to be actively pressed by the air bag and thereby stirs the pigment ink contained in the ink pack. For the purpose of introducing the pressurized air into the air bag, there is a need to connect the air bag with a compressed air supply mechanism provided in the inkjet printer when the cartridge is mounted to the inkjet printer.